string tied around the vessel. Veins are
not ligated unless very large (and even then only when other means are not
available) on account of the danger of causing phlebitis, or inflammation
of a vein. The ligature is tied around the end of the artery, but in some
instances this is difficult and it is necessary to include some of the
adjacent tissue, although care should be taken not to include a nerve. To
apply a ligature, it is necessary to have artery forceps (tweezers or small
pincers may suffice) by which to draw out the artery in order to tie the
string around it. To grasp the vessel it may be necessary to sponge the
blood from the wound so that the end will be exposed. In case the end of
the bleeding artery has retracted, a sharp-pointed hook, called a
tenaculum, is used to draw it out far enough to tie. The ligature should be
drawn tightly, so that the middle and internal coats will be cut through.

Another method of checking hemorrhage is called torsion. It consists in
catching the end of the bleeding vessel, drawing it out a little, and then
twisting it around a few times with the forceps, which lacerates the
internal coats so that a check is effected. This is very effectual in small
vessels, and is to be preferred to ligatures, because it leaves no foreign
body in the wound. A needle or pin may be stuck through the edges of the
wound and a string passed around between the free ends and the skin (Pl.
XXVII, fig. 10), or it may be passed around in the form of a figure 8, as
is often done in the operation of bleeding from the jugular vein.

ANEURISM.

A circumscribed dilatation of an artery, constituting a tumor which
pulsates synchronously with the beats of the heart, is called aneurism. It
is caused by disease and rupture of one or two of the arterial coats. The
true aneurism communicates with the interior of the artery and contains
coagulated blood. It is so deeply seated in cattle that treatment is out of
the question. Such abnormalities are ascribable to severe exertion, to old
age, to fatty or calcareous degeneration, or to parasites in the blood
vessels. Death is sudden when caused by the rupture of an aneurism of a
large artery, owing to internal hemorrhage. Sometimes spontaneous recovery
occurs. As a rule no symptoms are caused in cattle by the presence of
deep-seated aneurisms, and their presence is not known until after death.

A false aneurism results from blood escaping from a wounded artery into